Page 1 of 1
OOP Without interfaces
Posted: Tue Jun 12, 2012 11:32 pm
by Hydrate
This is just a really basic example I got bored and made when I got home from work today. It demonstrates the creation of a class, inheritance of that class and the creation of objects, all without using interfaces, or anything overly complicated to new users of Purebasic. I have no idea how useful it will be to anyone, but better to post it than for it to go entirely to waste.
Enjoy:
Code: Select all
; Simple Purebasic OOP example
; Format for classes:
; PROTOTYPES - Only necessary for methods not in parent classes. Declared first so that the structure can read it.
; STRUCTURE - Variables, then methods, order doesnt really matter. - METHODNAME.PROTOTYPE
; METHODS - Methods with 'CLASSNAME_' before them to distinguish between them and procedures
; CONSTRUCTOR - At the bottom so it can set all of the methods appropriately
;
;{ Class Rectangle
Prototype Rectangle_size(*this, width.i, height.i);
Prototype Rectangle_move(*this, x.i, y.i);
Structure Rectangle;
x.i;
y.i;
width.i;
height.i;
size.Rectangle_size;
move.Rectangle_move;
EndStructure;
Procedure Rectangle_size(*this.Rectangle, width.i, height.i);
*this\width = width;
*this\height = height;
EndProcedure;
Procedure Rectangle_move(*this, x.i, y.i)
Debug "moving";
EndProcedure;
; Constructor
Procedure Rectangle_(*this.Rectangle);
*this\size = @Rectangle_size();
*this\move = @Rectangle_move();
EndProcedure;
;}
;{ Class ColouredRectangle
Structure ColouredRectangle Extends Rectangle;
colour.l;
EndStructure;
; Method override for size
Procedure ColouredRectangle_size(*this.ColouredRectangle, width.i, height.i);
*this\width = width;
*this\height = height;
Debug "Coloured sizing instead!";
EndProcedure;
; Constructor
Procedure ColouredRectangle_(*this.ColouredRectangle);
Rectangle_(*this);
*this\size = @ColouredRectangle_size();
EndProcedure;
;}
; Rectangle myRect = new Rectangle()
Rectangle_(myRect.Rectangle);
myRect\size(myRect, 20,20);
Debug myRect\width;
; ColouredRectangle mycRect = new ColouredRectangle()
ColouredRectangle_(mycRect.ColouredRectangle);
mycRect\colour = RGB(20,12,20);
mycRect\size(mycRect,22,91);
Debug mycRect\colour;
Re: OOP Without interfaces
Posted: Wed Jun 13, 2012 1:24 am
by Demivec
Thanks for the example.
Re: OOP Without interfaces
Posted: Wed Jun 13, 2012 1:25 am
by skywalk
Seems rather compact and easy to follow.
Is there any need to free memory or a Destructor?
Re: OOP Without interfaces
Posted: Wed Jun 13, 2012 2:03 am
by rsts
Nice
Thanks for sharing.
Re: OOP Without interfaces
Posted: Wed Jun 13, 2012 7:28 am
by Hydrate
skywalk wrote:Seems rather compact and easy to follow.
Is there any need to free memory or a Destructor?
Because it uses none of the complex features in Purebasic (simply uses a struct), you can destruct an object simply by using the ClearStructure() command.
It also means that copying an object is very easy. You can do it with:
Code: Select all
myRect2.Rectangle = myRect.Rectangle
Debug myRect2\width;
Re: OOP Without interfaces
Posted: Wed Jun 13, 2012 9:59 am
by STARGÅTE
without interfaces, you must give the own object to the procedure.
mycRect\size(mycRect, 22, 91);
if that is not complicated, it is ok.
But an interface would not need it:
mycRect\size(22, 91);
Re: OOP Without interfaces
Posted: Wed Jun 13, 2012 1:17 pm
by inc.
mycRect\size(mycRect, 22, 91);
And beside this .... its almost the way of handling objects like PB does it already
RectSize(#myRectNum, 22, 91)
So approaches where you have to provide the object pointer to methods are object based, but not object orientated.
Theres a way on
32bit compiles, but seems to be unsafe .... and maybe not supported by future PB versions:
Code: Select all
Declare.l Test_get()
Declare.s Test_set(val.l)
Prototype.l Test_get()
Prototype.s Test_set(val.l)
Structure Test
get.Test_get
set.Test_set
Handle.l
EndStructure
Procedure.l Test_get()
Protected *this.Test
!MOV [p.p_this],Ebp
ProcedureReturn *this\Handle
EndProcedure
Procedure.s Test_set(val.l)
Protected *this.Test
!MOV [p.p_this],Ebp
*this\Handle = val
ProcedureReturn "bla"
EndProcedure
Procedure _createTest(Size.l)
If Size<SizeOf(Test)
Size = SizeOf(Test)
EndIf
Protected *this.Test = AllocateMemory(SizeOf(Test))
*this\get=@Test_get()
*this\set=@Test_set()
*this\Handle = 666
ProcedureReturn *this
EndProcedure
Procedure.l Test()
ProcedureReturn _createTest(0)
EndProcedure
*b.Test = Test()
Debug *b\get()
Debug *b\set(9999999)
Debug *b\Handle
Re: OOP Without interfaces
Posted: Wed Jun 13, 2012 3:25 pm
by ts-soft
inc. wrote:Theres a way on 32bit compiles, but seems to be unsafe .... and maybe not supported by future PB versions:
Code: Select all
Declare.l Test_get()
Declare.s Test_set(val.l)
Prototype.l Test_get()
Prototype.s Test_set(val.l)
Structure Test
get.Test_get
set.Test_set
Handle.l
EndStructure
Procedure.l Test_get()
Protected *this.Test
CompilerIf #PB_Compiler_Processor = #PB_Processor_x64
!MOV [p.p_this],Rbp
CompilerElse
!MOV [p.p_this],Ebp
CompilerEndIf
ProcedureReturn *this\Handle
EndProcedure
Procedure.s Test_set(val.l)
Protected *this.Test
CompilerIf #PB_Compiler_Processor = #PB_Processor_x64
!MOV [p.p_this],Rbp
CompilerElse
!MOV [p.p_this],Ebp
CompilerEndIf
*this\Handle = val
ProcedureReturn "bla"
EndProcedure
Procedure _createTest(Size.l)
If Size<SizeOf(Test)
Size = SizeOf(Test)
EndIf
Protected *this.Test = AllocateMemory(SizeOf(Test))
*this\get=@Test_get()
*this\set=@Test_set()
*this\Handle = 666
ProcedureReturn *this
EndProcedure
Procedure.l Test()
ProcedureReturn _createTest(0)
EndProcedure
*b.Test = Test()
Debug *b\get()
Debug *b\set(9999999)
Debug *b\Handle
Re: OOP Without interfaces
Posted: Wed Jun 13, 2012 9:52 pm
by inc.
Nice
Re: OOP Without interfaces
Posted: Tue May 17, 2022 8:01 pm
by chikega
10 years later .. still a nice example that I can learn from. Thank you.
